You need to have a house placement tool and 140k in the bank to place the New Magincia plots. 15 by 15 will go, but it takes some patience and precise aiming on most plots. 1 to 2 tiles directly away from the tombstone is where you should target. At least that is what we have found. If you don't then you will a "Housing can not be placed in this area" message. Hope this helps.